Biological Materials Science: On-Demand Oral Presentations
Sponsored by: TMS Functional Materials Division, TMS: Biomaterials Committee
Program Organizers: David Restrepo, University of Texas at San Antonio; Steven Naleway, University of Utah; Jing Du, Pennsylvania State University; Ning Zhang, Baylor University; Hannes Schniepp, William & Mary

Monday 8:00 AM
March 14, 2022
Room: Biomaterials
Location: On-Demand Room


Lightweight, Strong and Tough Structural Materials Inspired from Nature and Optimized by A.I.: Po-Yu Chen1; Cheng-Che Tung1; Ashish Ghimire1; Yen-Shuo Chen1; Yu-Yi Lai1; Chi-Hua Yu2; 1National Tsing Hua University; 2National Cheng Kung University
    Natural materials are often composites of organic and inorganic constituents self-assembled into complex hierarchical structures which possess remarkable mechanical properties, combining lightweight, high strength and high toughness owing to strengthening and toughening mechanisms from nano-, micro-, meso-, and macro-scales. Learning from Nature can lead to revolutionary breakthrough and innovation in Materials Science and Engineering. In this talk, representative biological structural materials, including nacre (layered), arthropod exoskeletons (helical), dragonfly wings (Voronoi), bamboos (gradient), and cuttlebone (cellular) are selected and investigated. Inspired from the structural designs of these natural materials, we further apply multi-scale simulation/modeling, genetic algorithm, machine learning, and A.I.-related approaches to optimize the bio-inspired designs and validated by 3D printing and mechanical testing. The structure-property relationships and toughening mechanisms are elucidated and key design principles and strategies are proposed. Novel cellular materials and composites inspired from Nature and optimized by A.I. could lead to broad potential applications in industrial fields.

Tuning the Cancer Microenvironment at Bone Metastasis Using the Cancer Testbed: Kalpana Katti1; Sharad Jaswandkar1; Haneesh Jasuja1; Hanmant Gaikwad1; Farid Solaymani1; Jiha Kim1; Anu Gaba2; Dinesh Katti1; 1North Dakota State University; 2Sanford Health
    Cancer that has metastasized to bone is essential incurable. The significantly altered environment at metastasis is responsible for the adhesion of cancer cells to bone and their proliferation at the bone-site. We have developed a nanoclay-based bone-scaffold for development of in vitro models of bone of breast and prostate cancer metastasis using commercial and patient-derived cancer cell lines. We use the testbed for screening drugs and discovery of metastasis-biomarkers. Adhesion forces between cancer cells and bone are measured using an aspiration-based AFM tip. This initial attachment is crucial for bone metastasis and progression of tumors. Mechanical cues are suggested by molecular simulations of integrins relevant to cancer cell attachment. Immunocytochemical imaging of cancer cells elucidates fundamental structural changes in the cells resulting from cell adhesion. Overall, we report the use of a cancer testbed to study progression of bone metastasis and for providing suitable mechanical and chemical cues against metastasis.

Nanoparticle Embedded Multifunctional Catheter for Multimodal Cancer Therapy: Hiep Pham1; Yufang He1; Jonghyun Park1; 1Missouri University of Science and Technology
    Current state-of-the-art to achieve hyperthermal therapy involves injection of gold nanoparticles into the target cancerous site and subsequent irradiation with NIR light to produce heat by the surface plasmon resonance effect. However, challenges with this approach include poor heat localization due to particle migration, toxicity concerns, cost, and overall impracticality with combined therapies. These issues are addressed in this work, where biocompatible and cost-effective copper (II) sulfide (CuS) particles are embedded into a bioresorbable polymer catheter that produce therapeutic temperatures when irradiated with NIR light. The results of this work indicate that hyperthermia therapy can be made more practical using the CuS-embedded catheter and has to potential to ease combination of hyperthermal therapy with traditional cancer treatments, such as brachytherapy and chemotherapy, to enhance their therapeutic efficacy.

Multidrug Delivery via Electrospun Core-shell Structured Nanofibers for Enhanced Post-surgical Healing: Hiep Pham1; Gracie Boyer1; Jonghyun Park1; 1Missouri University of Science and Technology
    In this work, a dual drug-loaded core-shell nanofiber enabled by electrospinning is developed. A fast-dissolving polymer loaded with a primary antibiotic drug serves as the thin shell and can achieve rapid drug delivery once immersed in an aqueous medium to suppress infections. Meanwhile, the core thermosensitive polymer serves dually as a stabilizing backbone to improve the spinnability of the shell and as a carrier to a secondary anti-inflammatory drug that can be released via a triggered rise in temperature. This temperature rise is triggered by the incorporation of magnetic nanoparticles in the core polymer, which produces heat once an alternating magnetic field is applied and creates openings in the core thermosensitive polymer enabling enhanced dissolution of the material and drug release. The electrospinning parameter impact is investigated and a characterization of dual drug-loaded core-shell structured nanofibers for drug delivery in relation to drug loading and drug release is conducted.

Cement-polymer Composite Structures Inspired by Molluscan Prismatic Layers: Shahbaz Khan1; Ling Li1; 1Virginia Tech
    Natural materials composed of highly organized ductile and brittle phases exhibit outstanding mechanical properties. The prismatic layers of bivalve mollusk shells, for example, are known to perform well under impact and abrasive loads. The prismatic layer architecture, characterized by 2D grain evolution, is composed of normally oriented variable diameter prisms in an organic matrix. The structural complexity arising due to grain evolution makes the modeling and fabrication of such composites challenging. In this research, we use a 2D grain growth algorithm to model the prismatic structures with controlled grain growth rates and volume fractions. Next, we 3D print the matrix which is subsequently infiltrated by cement paste to produce prismatic layer-inspired cement-polymer composites. The indentation tests are performed using a spherical-tip indenter to evaluate the localized deformation behavior. Localized mechanical properties like hardness, reduced modulus, abrasion resistance, and crack growth resistance are evaluated.

Decussation in Human Enamel: Descriptions of the Complex Pattern of the Enamel Rods: Cameron Renteria1; Susana Estrada Hernandez2; Juliana Fernández-Arteaga2; Jack Grimm1; Alex Ossa2; Dwayne Arola1; 1University of Washington; 2Universidad EAFIT
    Enamel is the outer-most layer of mammalian teeth and serves as a multi-functional coating that provides protection to the vital underlying tissues. In the permanent dentition of humans, tooth enamel must resist fatigue and wear over a lifetime, which extends over tens of millions of cycles. The damage tolerance of enamel is unparalleled by any other naturally occurring mineralized tissue. Previous studies have attributed this behavior to composition gradients, mineralogical variations, and microstructure across the enamel thickness. More recently, however, a distinct aspect of the meso-scale structure regarded as decussation has been credited for its resilience. Decussation refers to a complex weaving pattern of the enamel rods that is exhibited by the inner enamel. Details of this pattern have been elusive. This study aimed to develop a more comprehensive view of decussation in human enamel and presents a preliminary “unit-cell” concept for 3D printing materials with enamel-like microstructure.

The Influence of Reactive Oxygen Species in in Vitro Corrosion Resistance of CoCrMo: Sangram Mazumder1; Mangesh V. Pantawane1; Narendra B. Dahotre1; 1University of North Texas
    The electrochemical (corrosion) products from the CoCrMo implants may stimulate the in vivo immune and inflammatory responses leading to local inflammation. In light of this, here, we report an in vitro electrochemical test in presence of the reactive oxygen species; hydrogen peroxide, often found in real-time in vivo inflammatory conditions. Open circuit potential, potentiodynamic polarization Tafel plots and electrochemical impedance spectroscopy indicated change in electrochemical response of the laser-additively fabricated CoCrMo in presence of small amount of hydrogen peroxide in simulated body fluid. Such results indicated inflammation-induced electrochemical activity of the laser additively fabricated CoCrMo samples. X-ray diffraction was used in phase identification of the laser-additively fabricated CoCrMo. Scanning electron microscopy was used to observe the microstructural traits and local corrosion pattern. The electrochemical products were further characterized using X-ray photoelectron spectroscopy.

Controlled Drug Diffusion Kinetics in HEMA-backbone Hydrogels for Ocular Disease Treatment: Parker Toews1; Jeff Bates1; 1University of Utah
    Drug diffusion kinetics were studied as a function of hydrogel cross-linking density and porosity. By varying concentrations of cross-linker, triethylene glycol dimethacrylate (TEGDMA), in a 2-hydroxyethyl methacrylate (HEMA) backbone hydrogel, it was demonstrated how the kinetics could be controlled to allow for controlled drug delivery of Timolol, a glaucoma medication. Cross-linking density was determined using both mathematical models and experimental techniques, such as FTIR and UV-Vis. Using the Beer-Lambert Law, the partition coefficient could be determined. Porosity was studied by using SEM to evaluate the surface of the hydrogel. Mechanical techniques, like DMA, were used to supplement the inferences developed from spectroscopy.

A Study of the Composition and Mechanical Properties of Aprismatic Tooth Enamel Afflicted by Amelogenesis Imperfecta: Jack Grimm1; Dwayne Arola1; 1University of Washington
    Amelogenesis is the biological process that produces tooth enamel, the hardest tissue in the body. When successful it results in a biocomposite with ~96 wt.% hydroxyapatite mineral nanocrystals surrounded by ~1 wt.% organic protein and ~3 wt.% water. Enamel is surprisingly resistant to fatigue and fracture due to its complex hierarchical microstructure and unique decussating patterns of the enamel rods. Genetic defects can interrupt enamel formation, resulting in excessive organic content, premature termination of amelogenesis, or production of aprismatic enamel, depending on the affected gene(s). Collectively, these mutations are described as the genetic disease Amelogenesis Imperfecta (AI), which causes stained, sensitive, and mechanically weak teeth. Here, a materials science description of the mechanical and compositional characteristics of AI-afflicted enamel is compared to other enamel systems, including healthy human enamel and the primitive, aprismatic enamel of crocodilians. A better understanding of AI enamel could lead to therapeutic options for patients.

Biodegradable Molybdenum/Polybutylene Adipate Terephthalate Conductive Paste for Flexible and Stretchable Transient Electronics: Jaeyoung Yoo1; Kyung-Sub Kim2; Jun-Seok Shim2; Jahyun Koo3; Seung-Kyun Kang2; Hyuck Mo Lee1; 1Kaist; 2Seoul National university; 3Korea university
    Biodegradable electronics is an emerging field of technology capable of reducing the increasing electronic waste originating from the rapid development of bio-integrated devices and skin adhesive patches. Through an advantageous solution process, biodegradable conductive pastes can be employed in various applications of soft and flexible devices. Herein, a biodegradable conductive paste composed of Mo microparticles and polybutylene adipate terephthalate (PBAT) exhibiting excellent mechanical flexibility and stretchability is reported, while also demonstrating substantially superior mechanical and conductive properties compared with previously reported biodegradable polymer matrices such as poly butanedithiol 1,3,5-triallyl-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione pentenoic anhydride and Candelilla wax owing to the significant elongation of PBAT. Moderate dissolution in phosphate buffer saline accomplishes its full biodegradability and programmable lifecycle. The practical implications of the Mo/PBAT pastes are demonstrated in numerous biodegradable electronic applications such as electrodes, strain and temperature sensors, joule heaters, and interconnectors.

Optimization of Multi-physical Properties of Gradient Cellular Structures Inspired by Termite Nests: Wen-Fei Chen1; Cheng-Che Tung1; Tsung-Hui Huang1; Po-Yu Chen1; 1National Tsing Hua University
    Termites are known as outstanding builders in nature that can create multifunctional mounds and even develop adequate ventilation and temperature regulation systems to conquer severe environmental conditions. Notably, based on our observations from micro-CT and SEM, the termite nest possesses a three-dimensional continuous cellular structure with a high surface-to-volume ratio which shares similar features with the triply periodic minimal surface (TPMS) structure. Inspired by the structure of termite nest, we design a series of modified cellular structures with gradient periodicity and investigate the heat transfer and sound penetration properties with varying structural parameters. By applying 3D printing technology and finite element simulation, compressive mechanical properties, heat distribution and sound attenuation behaviors are further evaluated and discussed. Moreover, we can optimize these properties to develop multifunctional cellular structures based on the analytical results. Consequently, the optimized structure inspired by the termite nest can further broaden potential applications.

Mimicking the Glioblastoma Cells' Microenvironment via Anisotropic Sub-microscaled Surface Patterns and Enabling Directional Adhesion of Filopodia on Metallic Biomaterials: Benay Uzer-Yilmaz1; 1Izmir Institute of Technology
    Glioblastoma (GBM) is the most aggressive brain tumor type and contact guidance via aligned-nanoscaled white matter tracts plays crucial role for their invasion. In this study, this microenvironment was mimicked by tensile loading 304L stainless steels up to 5% and 25% strains. Microstructural evolution and topography of surface relief were analyzed via AFM and SEM. Cell morphology was investigated with SEM and immunofluorescence technique. Spacing of directional surface patterns decreased down to submicro-scale with deformation. Kinking of filopodia was captured on 25% deformed-sample evidencing constraint induced by deformation markings and exerted contact forces. Findings suggest that deformation markings can block filopodia movement and suppress cells’ tendency for invasion. Filopodia elongation orthogonal to aligned submicro-scaled markings further suggests that anisotropic topographical cues could be used for directing cells along desired pathways. These results can be used to design metallic implants for therapeutic purposes targeting migration pathways of GBMs and controlling invasion.

Tissue Derived Nanocomposite for Embolization: Jingjie Hu1; 1North Carolina State University
    Transarterial embolization is a minimally invasive procedure to selectively deliver embolic agents using a catheter into arteries to occlude diseased or injured vasculature for therapeutic intent. In this study, a decellularized cardiac extracellular matrix (ECM)–based nanocomposite gel is developed to provide outstanding mechanical stability, catheter injectability, retrievability, antibacterial properties, and biological activity to prevent recanalization. The malleable and shear-thinning nature of the nanocomposites gel allows the formation of an impenetrable solid cast to fill various vessel geometries and sizes, avoiding recurrent bleeding, and provides the versatility that cannot be achieved by clinically used agents. The embolic efficacy of gel is shown in a porcine survival model of embolization in the iliac artery and the renal artery. With its proregenerative, antibacterial properties coupled with favorable mechanical properties, the bioactive ECM–based nanocomposite gel enables wide tunability as the next-generation embolic agents with the potential to treat a broad range of vascular diseases.

On the Intrinsic Mechanical Properties of Individual Biogenic Mineral Units in Biomineralized Skeletons: Zhifei Deng1; Ling Li1; 1Virginia Polytechnic Institute and State University
    Bio-inspired study on replicating the superior damage tolerance requires a detailed understanding of the intrinsic properties of biomineral units. Here, we investigate and compare the intrinsic properties of biogenic calcite (Atrina rigida) and aragonite (Sinanodonta woodiana) by conducting micro-bending experiments on the separated prismatic building blocks. Analyzed bending results indicate that the biogenic calcite has a higher modulus (36.24±14.4 GPa for A. rigida vs. 29.9±10.5 GPa for S. woodiana) and strength (446.5±141.5 MPa for A. rigida vs. 338.6±63.2 MPa for S. woodiana) than the biogenic aragonite, while the nanoindentation results indicate the opposite trend. Further systematic fractographic analysis suggests that the biogenic calcite fractures like amorphous glass, while the biogenic aragonite resembles polycrystalline ceramics. These contradictory behaviors of biogenic calcite and aragonite under tension- (micro-bending) and compression-dominated (nanoindentation) loading conditions are attributed to their different intrinsic structures, i.e., intracrystalline organic inclusions in single-crystal calcite vs. interlocked nanograins in polycrystalline aragonite.

Novel Expandable Architected Breathing Tube for Improving Airway Securement in Emergency Care: David Restrepo1; Carlos Bedolla1; James White1; David Berard1; R. Lyle Hood1; 1University of Texas at San Antonio
    Life-saving interventions utilize endotracheal intubation to secure a patient's airway, but the performance of the clinical standard of care endotracheal tube (ETT) is inadequate. Patients undergoing prolonged intubations frequently experience health complications such as tracheal stenosis, pneumonia, and necrosis of the tracheal tissue as current ETTs are not designed for extended use. In this talk, we will present an improved ETT design that seeks to overcome these limitations by utilizing unique geometries which enable a novel expanding cylinder. The mechanism provides a better distribution of the contact forces between the ETT and the trachea, which should enhance patient tolerability. In-vivo tests show that at full expansion, the new ETT exerts pressures in the trachea well within the recommended standard of care. Also, preliminary manikin tests demonstrated that the new ETT can deliver similar performance in terms of air pressure and air volume when compared with the current gold standard ETT.